Air cargo is any goods transported in an aircraft, such as luggage, freight, and mail. Air cargo can be transported in either a passenger or cargo aircraft. Often, air cargo is stored in a shipping container, which is then placed onto a cargo pallet and restrained using restraint nets or straps. The restraint nets or straps have an elastic characteristic, which allows some movement of the container with respect to the pallet during flight.
Shipping containers come in standard sizes. For example, an ISO 1C container has a width and height of 8 feet, and a length of 20 feet. The ISO 1CC containers have the same width and length as the ISO 1C container, but are 6 inches taller having a height of 8 feet 6 inches.
Cargo pallets also come in standard sizes. For example, a NAS 3610-2G1P pallet, also referred to as a 20 foot pallet, is a 96 inch×238.5 inch cargo pallet. These 20 foot pallets are commonly used for transporting air cargo and are placed into standard cargo lanes in the aircraft.
Per regulations, a shipping container is not permitted to contact the interior structure of the aircraft. If a container is too tall after loading it onto a cargo pallet in one of the standard pallet locations, it may be possible to shift the container on top of the pallet towards the centerline of the aircraft and away from the interior structure of the aircraft to achieve the required spacing between the container and the aircraft structure. After shifting the container, a restraining mechanism is necessary to prevent the container from moving back towards the interior structure of the aircraft during flight. The standard restraint nets and straps allow too much movement to be used in this container shifting application.